Liquid exfoliation of 2D MoS2 nanosheets and their utilization as a label-free electrochemical immunoassay for subclinical ketosis. Issue 30 (21st July 2017)

• Record Type: Journal Article
• Authors: Tuteja, Satish K.; Duffield, Todd; Neethirajan, Suresh
• Is Part Of: Nanoscale. Volume 9:Issue 30(2017)
• Page Start: 10886
• Page End: 10896
• Publication Date: 2017-07-21
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c7nr04307d
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Schematic illustration of 2D MoS2 exfoliation into nanostructures using sonication, and subsequent attachment to the working surface of gold modified SPEs by electrodeposition. By virtue of bioconjugation, the MoS2 modified SPEs were then functionalised with βHBA antibodies to develop a biointerface. Abstract : We report the step-by-step fabrication of a 2D MoS2 nanostructure-based disposable electrochemical immunosensor to detect β-hydroxybutyrate (βHBA), a novel subclinical ketosis biomarker. The MoS2 nanosheets were exfoliated in the liquid phase by ultrasonication, and then followed by deposition on gold colloid modified screen-printed electrodes (Au-SPE). The MoS2 -modified electrodes were thoroughly characterized by physical, electrochemical as well as spectroscopic techniques, and the obtained results indicate the successful and irreversible electrodeposition of MoS2 nanosheets. These MoS2 -modified disposable electrodes were subsequently bioconjugated with anti-βHBA antibodies and then employed for the label-free immunosensing of the βHBA biomarker to detect subclinical ketosis. A simple electrochemical Differential Pulse Voltammetry (DPV) technique based immunodetection was realized for the sensing of varying concentrations of βHBA antigen. The bioassay demonstrated remarkable sensitivity and specificity having a dynamic linear response range of 0.7 mM to 10 mM for βHBA in standard antigen solutions, spiked serum, blood, milk and clinical samples, with linear results being obtained with R 2 ∼ 0.9923. The sensor electrodes were also studied with other relative interferents to investigate cross reactivity and non-specificity. These electrodes showed a linear, specific, reproducible and stable response towards the βHBA antigen over a wide range of concentrations.